Axial impact driving tool



Nov. 14, 1961 R. w. HENNING AXIAL IMPACT DRIVING TOOL 2 Sheets-Sheet 1Filed Oct. 21, 1958 IN V EN TOR. Roam? M HE/V/V/A/G B A TTORNEY Nov. 14,1961 R. w. HENNING 3,008,361

AXIAL IMPACT DRIVING TOOL Filed Oct. 21, 1958 2 Sheets-Sheet 2 INVENTOR.ROBERT W. HENNING ATI'OK/YE Y Patented Nov. 14, 1961 Free 3,008,361AXIAL IMPACT DRIVING TOOL Robert W. Henning, Fairview, Ohio, assignor toOlin Mathieson Chemical Corporation, East Alton, ill, a corporation ofVirginia Filed (lot. 21, 1958, Ser. No. 768,717 7 Claims (Cl. 8152.35)

This invention relates in general to a hand tool for driving nails,pins, studs and the like and specifically for driving fasteners ofspecial design for fastening into materials including concrete and steelparticularly and for performing a combination of associated operationsalternately with and related to driving of various sizes and shapes offasteners.

The advantages of such a multi-purpose tool for various types offasteners will be obvious not only to building construction workmenregularly employed in nailing into wood, concrete and metal in factoriesand homes, but also to the do-it-yourself handyman concerned at randomoccasions with many operations associated with installation offasteners.

Therefore, the general object of this invention is to provide a handtool of relatively simple construction characterized by durability ofits operating parts as well as flexibility of its use wtih more than onetype of fastener and of such tool size and shape as'to permit access ofthe tool into most places including even those of limited accessibilityrequiring such installations. Still another object is to provide a novelarrangement in a manually operable tool, which facilitates the rapidaccomplishment of the tool operators tasks with improved control ofpenetration.

The type of tool heretofore used generally comprises some sort of atubular housing and guide for doing no more than guiding and setting onekind of fastener in the bore of the guide for lateral support and alsoincludes an axially movable plunger or anvil for driving the fastenerwhile guided into the surface. The outer portion of the housing sometimeincludes a suitable handle to enable manual guidance with one hand aswell as manual power application with the other with the aid of ahammer, or the like. A sturdy tool capable of doing more thingsassociated with such driving and adapted for handling of more than onekind of fastener would be desirable; and such a tool is disclosed here.

In accordance with this invention, the objects are attained by theprovision of a tool so shaped at the forward end as to present to thework a portion capable of fitting into a variety of places and having anarrangement and design of its parts for doing a variety of tasks in anadaptable manner with readily interchangeable working parts. The tool ofthis invention is primarily an impact too-l adapted for driving intowork surfaces fasteners of various types and/or of various sizes byimpact, but the tool is adaptable for applying torque as well. With aminimum of alteration, involving coupling with an auxiliary part, thetool is adapted to driving a screw fastener of a kind especially adaptedfor handling by means of application of both impact and torque throughthe tool. With a still further and minor change involving the samecoupling, the tool is adapted to operate a star drill preparatory toinstallation of the screw fastener. The tool is especially adapted tosetting screw fasteners of various types initially with impact into eventhe narrowest of quarters and finally driving these fasteners hometogether with rotation where necessary.

One feature of the tool lies in limiting the travel of the driver so asto allow application of thrust force to the fastener until it is drivento the desired extent and thereafter diverting the force to avoidoverdriving of the fully driven fastener and injury to the forceapplying tip of the driver. In a preferred arrangement, the tip itselfis a separate and replaceable part. Another feature of the tool residesin the size of the front end of the tool and the coupling means disposedthere for mounting readily detachable tool attachments and which adaptthe tool to transmit even high impact blows without impairing orinterfering with the function of the coupling. Another feature lies inthese various auxiliary parts, and particularly in a special auxiliarypart forming another attachment which may be coupled to the front end ofthe device for adapting it to driving of fasteners of lesser diameterand/ or to driving them only partially impaled leaving the rear end ofthe fastener protruding to a desired standoff distance.

How these objects are attained will become more apparent from thedescription of the tool and its parts shown in the drawing in which:

FIG. 1 is a longitudinal cross sectional view of a preferred embodimentof the driving tool in side elevation with a preferred attachment forhandling certain impact driveable fasteners;

FIG. 2 is a front end view taken on line II--II of FIGURE 1 with theauxiliary fastener attachment shown in FIGURE I removed to show the toolin condition without any such attachment ready for driving a stilllarger diametered fastener flush into the surface;

FIG. 3 is a side elevational view, partly in cross section, showinganother auxiliary attachment adapting the tool for various purposes suchas for receiving bits for making holes by drilling and for receiving achuck, for driving different types of fasteners;

FIG. 4 is an exploded semi-perspeotive side elevational view of aself-tapping screw fastener together with a special chuck, partly incross section, by which it may be positively driven according to thisinvention;

FIG. 5 is an enlarged fragrnentary and sectional view of the specialthread coupling shown in FIGURE 1 to take all the various attachments;

FIG. 6 is an enlarged fragmentary view in cross section of a part ofFIGURE 1 modified according to another embodiment;

FIGURE 7 is a side elevational view of the device shown in FIGURE 2;

FIGURE 8 is an end view taken on line VIII-VIII of FIGURE 7. 1

Basically, the tool comprises a resilient grip 9 of rubber, plastic orthe like elastomeric material, a plunger 17 having a separable drive rod18, a plunger and drive rod guide and holder member 10 with a specialsize nose 31 with threaded coupling means 30 for connecting variousspecial attachments to the front end of the tool so as to extend itsusefulness to the fullest.

Special fastener holder attachments shown are contempl-ated.

Grip 9 consists of an elastomer such as a'suitable rubber, polyurethaneor polyethylene secured all along its bore 13 to the guiding and holdermember 10 by adhesion or friction. Grip 9 is flared rearwardly and istapered forwardly to a slender extension, which is formed withlongitudinally extending ribs 8 as shown in FIGURE 2 and at the rear thegrip is formed with an integral hand guard 11. Ribs 8 permit the grip tobe grasped in an advantageous manner for applying atorque manually whendesired. The guard 11 extends outwardly to protect the hand of theoperator from any misdirected hammer blow and has flat sides 16 forgiving a roll resisting moment as a result of the combined peripheralenlargement at 11 and the small number of sides shown to prevent rollingof the tool, when laid on its side. The grip 9 and guide member 10 thusform a housing; and a portion of grip 9 of the housing permanentlyextends inwardly opposite guard 11 (FIGS. 1 and 8) as a num- 9 a ber ofprotrusions 12 integrally molded with the grip in the form ofcircumferentially spaced fingers, or longitudinal serrations, rubbing onpart of the cylindrical surface of the plunger for frictionallyretaining the plunger 17 and its drive rod 18 at all times as part ofthe tool unless the plunger and rod are withdrawn at the will of theoperator for cleaning or other maintenance purposes. Protrusions 12 dragon the cylindrical plunger surface '7 which is considerably enlarged ascompared to the surfaces of the drive rod 18 from which surface 7 isspaced. This arrangement together with a suitable large number, or area,of protrusions makes possible the attainment of the proper degree offrictional gripping of the plunger independently of the operator butwithout interfering excessively with its driving movement.

The upper and exposed extension of the plunger 17 has an enlarged head19 fastened thereto by a press fit with splines 21 so that the plungermay better receive blows and may better by manipulated by hand. Driverod 18 in turn is secured in recess 23 of the plunger by splines 22. so

i that it may not only be detached and replaced, if necessary, but alsoto better withstand the shock of hammer ing without early fracture orloosening.

The assembled plunger unit is mounted in the steel barrel of the housingso that the plunger 17 is pretty nearly all receivable in the enlargedand elongated bore of the rear end extension of the guide member or tube10 to get the piloting actionfound so necessary to proper driving of thefasteners Z, or the like, to penetrate into hard bodies such as 1, whilerod 18, which forms an extension of the plunger, is slidably journalledin reduced bore 6 at the front end of the guide tube.

Between the bores 6 and 15 there is a load limiting shoulder whichprevents excessive overdrive and penetration of the fastener when theeffective rod length and the fastener lengths are properly proportioned.It is contemplated that for the most exacting installations, either therod 18 is changed in length or, a predetermined length of the sleeveinsert 5 (FEGURE 6) is slipped on it and positioned adjacent splined end22 in any suitable way. Since only a few standard lengths of fastenersare employed only a few different lengths of drive rod and/or sleevesare needed. When plunger 17 bottoms onrshoulder 2t}, excessive impact isdiverted from the fastener to the holder 10 and to the attachment 41through the special threaded coupling, including threads and When usedwithout attachments the tool is as shown in FIGURE 2 and is adapted forhandling fasteners having at least a head, if not the whole shank, ofthe same diameter as the front bore 6, i.e., of the same diameter as theoperative end 24 of the rod 18.

Mounted in the recess 14 at the guard end 11 is a specially toughenedand hardened short length of pin 7 which serves with attachments eitheras a bit, chuck or fastener knock-out pin 25 or more importantly as areplaceable extension 25 for the rod 18 especially for coaction with theattachment 41, as shown in FIGURE 1. As best seen in FIGURE 2, the frontend 31 of the tool free of any attachment is of smallest outer diameterand has a special coupling thread 3! as well as having a washer or discreceiving recess 27 and two opposing bevels 28 and 29 defining anincluded angle of about as shown in FIGURES 1, 2 and 7. These togetherwith the small exterior diameter of about of an inch have been found toprovide a combination adapted for use in the greatest, number of.installations ordinarily met, despite the greatest variety of jobs. Thisentire slender front end 31extends longitudinally at least 7 of an inch,but the very tip of this end extending back for a length of about of aninch has a still further reduced diameter of about /2 of an inch beveledat opposite sides to form an included angle of about 40 as shown at 28and 29.

Bore 6 and rod 18 are of about inch diameter selected to fit this sizeof fastener found most useful.

For handling fasteners of lesser diameter than this size, such asfastener 2 of FIGURE 1, and especially those threaded at the rear end 3-and needing a fixed protrusion from work object 1, there is provided thebarrel attachment 4-1 of FIGURE 1 forming another guiding and holdingmember for. such a fastener thereby providing a secondaly holder knurledat 42 for handling it for putting it on and taking it off.

Secondary holder or attachment 41 is shown as a circular cylindricalbody having a large recess 43 at one end internally threaded at 49 tomate with the modified external threads 30 of the barrel for secure butdetachable barrel mounting designed to carry the greatest stressapplicable manually during pounding. At the opposite end is a smallerfastener receiving recess 44, acted on by a captive ball 47 mounted incross bore 46 and biased therein by ball detent spring 48 to extend intothe recess and thereby yieldably retain in it the fastener 2, while theother end of the ball spring is held by bore plug 49.

Between these end recesses is an intermediate and connectinglongitudinal bore of substantially the same diameter as rod 18 and bore6 for receiving the wear and breakage resistant driver end piece 25 orpin 25x, at least the former having an end recess for receiving the endof the smaller fastener 2 in alignment therewith. When secondary holders1 is attached to barrel 10, the driver piece 25 is constrained tolimited movement in bores 6 and 45 for. driving the fastener Z withcontrolled partial penetration to a predetermined distance.

This function of the tool is hard on piece 25 which eventually isbattered at the recess 26 on account of the tolerances of fit andalignment with the end of the fastener and variation therewithin. Itsreplacement is made easy as disclosed and the flat-ended drive rod 18 ispreserved.

Another attachment is the tapered chuck, or drill bit, or screw driverholder 51, FIGURE 3, knurled at 52, which, however, primarly functionsto hold a special fastener driver adapter 56 which is tapered at one endto lit with a grip in tapered bore 54- of the holder from which it maybe readily removed, if desired, by a drift pin pushed into sideextractor hole 58. Holder 51, similarly to secondary holder 41, has anenlarged bore 53 internally threaded at St} to mate with coupling thread30.

At the other end, adapter 56 has any suitable polygonal socket or recess57 also tapered to fit with a similarly tapered polygonal, preferablyfive sided, driving tang 63 on the special self-penetrating fastenerpointed at 61, self tapping sheet metal screw 3 having threads 62. Thetapered tang 63 holds screw 60 in recess 57 until the driving is done.0n impact applied by the plunger assembly,

point 61 accomplishes a penetrating puncture and on ap plication oftorque threads 62 will drive screw 69 up to the hilt 64, whereupon thewhole tool is pulled off the screw.

To permit all this interchangeability and variety of functions, there isprovided a specially modified thrust carrying coarse threaded couplingof diminished thread form (see the enlargement of FIGURE 5) which willnot lock up. Preferably the tooth forms 3t) and 4t and 50 is finelyshaped such as that of a standard 20 to-the-inch V-type thread but thespacing is coarse such as that of a standard 11 to-the-inch thread as at32. To make the male thread 30 the thread chaser of 11 tooth pitch iscut away partially at the crests, to leave only a thread protrusion ofabout 0.930 of an inch from about the pitch diameter at the resultantwidened root. For making the female thread, an oversize hole of aboutpitch diameter is tapped as for a 11 tooth pitch, leaving an indentationof somewhat less than but adequate to take the male protrusion.Similarly modified standard threads of 12 and 14 to the inch are alsosuitable but the disclosed coarser modified /8 inch screw is preferred,for speed of assembly and disassenrbly, as well as for strength andability to resist lock-up. In the /8 inch size found preferable, threadsof 16 or more to the inch are too fine for modification in accordancewith this invention. Regular coarse threads cut full depth should not beemployed here because they will weaken the slender front end, Which isfixed in size both internally and externally, thereby providing a thinwalled nose portion 31 small enough to adapt it for entry into tightquarters as in fastening at the bottom of shallow but narrowdepressions.

It will be understood that those skilled in the art may make furtherchanges and modifications without departing from the spirit and scope ofthis invention, which, therefore, should not be limited except as setforth in the appended claims.

What is claimed is:

1. An axial-impact tool for driving narrow elongated elements foraccomplishing penetrative fastening into the surface of a work objectcomprising a hollow metal holder having a through bore axially thereof,said bore having a reduced diameter portion at the forward part of saidholder and an enlarged diameter portion at the opposite part of saidholder, said portions being connected by a rigid shoulder at a locationintermediate said parts;

an elongated plunger slida-bly mounted for axial guidance in saidenlarged diameter portion, said plunger being provided with meansforming an impact-blow receiving rear end and being long enough relativeto said shoulder location to maintain said rear end out of said boreeven when said plunger is slid into said shoulder; said plungerincluding a reduced drive rod;

cooperating means on said plunger and rod for detachably connecting saidrod to extend forwardly rom said plunger to a predetermined lengthadapted for slidable reception and axial guidance in said reduceddiameter portion;

an outer casing of flexible material mounted on said holder whereby saidcasing extends outwardly from said holder adjacent said opposite holderpart and forms thereat a hand grip wherefrom the front end of theforward part of said holder protrudes as a thin walled nose of lesserouter diameter;

a hardened metal impact-receiving end piece forming a separate rodextension movably mounted for impact reception at said front end of thetool between said rod and elements;

a hollow secondary holder member;

said nose being provided with male coupling means detachably mountinsaid member at said front end, said coupling means being of the quickassembly and disassembly type capable of taking said impact axiallywithout either breaking or jamming against assembly and disassembly ofsaid member;

said shoulder location and drive rod length extending from said plungerbeing related to limit the slidable plunger movement and slidablereception of said rod, whereby at least one of said holder and member,when the latter is mounted, guides said end piece and elements duringdriving and also takes said impact blow when said plunger is slid intosaid shoulder and whereby said plunger takes said impact blow to saidelements.

2. The combination of claim 1 wherein the secondary holder member is anadapter for receiving elements of sizes and configurations diiferentfrom those of elements receivable in the reduced diameter portion of theholder; and wherein the coupling means is a special thread formation offine external thread form axially separated to a course pitch by anintervening widened fiat root upraised to about course pitch diameter toextend outwardly from normal course root and adapted for engagement witha complementary thread formation on said member of fine internal threadform axially separated to a course pitch by an intervening widened flatcrest depressed from normal course crest to about course pitch diameterfor disposition spaced outwardly opposite said flat root.

3. The combination of claim 1 wherein the impact-receiving end piece hasa configured,

recessed outer end for receiving and guiding the likeconfigured end ofan element.

4. An axial-impact tool for driving narrow elongated elementsforaccomplishing penetrative fastening into the surface of a work objectcomprising a hollow metal holder having a through bore axially thereof,said bore having a reduced diameter portion at the forward part of saidholder and an enlarged diameter portion at the opposite part of saidholder, said portions being connected by a rigid shoulder at a locationintermediate said parts;

an elongated plunger slidably mounted for axial guidance in saidenlarged diameter portion, said plunger being provided with meansforming an impact-blow receiving rear end and being long enough relativeto said shoulder location to maintain said rear end out of said boreeven when said plunger is slid into said shoulder; said plungerincluding a reduced drive rod;

cooperating means on said plunger and rod for detachably connecting saidrod to extend forwardly from said plunger to a predetermined lengthadapted for slidable reception and axial guidance in said reduceddiameter portion;

an outer casing of flexible material mounted on said holder whereby saidcasing extends outwardly from said holder adjacent said opposite holderpart and forms thereat a hand grip wherefrom the front end of theforward part of said holder protrudes: as a thin walled nose of lesserouter diameter;

said nose being provided with male coupling means for detachablymounting a hollow secondary holder member at said front end, saidcoupling means being of the quick assembly and disassembly type capableof taking said impact axially without either breaking or jamming againstassembly and disassembly of said member, said coupling means consistingof a special thread formation of fine external thread form axiallyseparated to a course pitch by an intervening widened flat root upraisedto about said course pitch diameter to extend outwardly from normalcourse root and adapted for engagement with a complementary threadformation on said member of fine internal thread form axially separatedto a course pitch by an intervening widened flat crest depressed fromnormal course crest to about said course pitch diameter, for dispositionspaced outwardly opposite said flat root;

said shoulder location and drive rod length extending from said plungerbeing related to limit the slidable plunger movement and slidablereception of said rod, whereby at least one of said holder and member,when the latter is mounted, guides said elements during driving and alsotakes said impact blow when said plunger is slid into said shoulder,said holder guiding said elements during driving when said memher isdetached, and whereby said plunger takes said impact blow to saidelements.

5. The combination of claim 4 including a mounted hollow secondaryholder member and wherein an integral partof the casing extendsoutwardly and forwardly to form alternately longitudinal ribs andgrooves between the forward and opposite parts of the holder foradapting said member and the element to the application of torquemanually, while an integral part of said casing extends rearwardlybeyond said opposite part and inwardly between said opposite part andthe impact blow receiving rear end to fully engage a fixed portion ofthe mounted plunger for continuous and uniform frictional retention ofsaid plunger on the tool. 1 a

6. An axial-impact tool for driving narrow elongated elements foraccomplishing penetrative'fastening into the surface of a work objectcomprising 1 a hollow metal holder having a trough bore axially thereof,said bore having a reduced'diameter portion at the forward part of saidholder and an enlarged diameter portion at the opposite part of saidholder,

said portions being connected by a rigid shoulder at a locationintermediate said parts;

an elongated plunger slidably mounted for axial guidance in saidenlarged diameter portion, said plunger being provided with meansforming an'impact-blow receivingrear end and being long enough rel'ativeto said shoulder location to maintain said rear end out of said boreeven when said plunger is slid into said holder whereby said casingextends outwardly from.

said holder adjacent said opposite'holder part and forms thereat a handgrip wherefrom front end of V the forward part of said holder protrudesas a thin walled nose of lesser outer diameter, while an integral partof said casing extends rearwardly beyond I said opposite part andinwardly between said opposite part and impact blow receiving rear endto 1 fully engage a fixed portion of said mounted plunger for continuousand uniform frictional retention of a said plunger on said tool inmounted relation;

said nose being provided with male coupling means for detachahlymounting a hollow secondary holder member atvsaid front end, saidcoupling means being of the quick assembly and disassembly type capableof taking said impact axially without either breaking or jamming againstassembly and disassembly of said member; a

said shoulder location and drive rod length extending from said plungerbeing related to limit slidable plunger movement and slidable receptionof said rod, whereby at least one of said holder and member, when thelatter is mounted, guides said elements during driving and also takessaid impact blow when said plunger is slid into said shoulder, saidholder guiding said elements during driving when said member isdetached, and whereby said plunger takes said impact blow to saidelements.

7. The combination of claim 4 wherein the thin walled nose is exteriorlybeveled on two opposite sides to facilita-te its protrusion into narrowdepressions at the surface of the work object and is interiorly recessedaround the open front end of the bore at opposite sides intervening saidtwo beveled sides for reception of washers, discs, and the like.

References Cited in the tile of this patent UNITED STATES PATENTS1,458,961 Williams June 19, 1923 2,455,270 Ravella Nov. 30, 19482,602,360 Berninger July 8, 1952 2,787,178 Maxim Apr. 2, 1957 2,839,754Pfafi June 24, 1958 FOREIGN PATENTS 924,131 France Mar. 3-, 1947 998,339France Sept. 19, 1951

